In the brewing industry, alkaline cleaning solutions have traditionally been used with hot water to clean the interior of brewing vats and kegs. Traditionally, these alkaline solutions have been used at pH levels of between 12-14. In addition, some of these alkaline solutions contain additional additives to assist in the cleaning and sanitation process including, for example, various surfactants and sanitization chemicals, i.e. “bleach”.
One downside of using the traditional alkaline cleaning solutions is that their effectiveness can be reduced in the elevated carbon dioxide (CO2) environments found within brewing vats and kegs. In order to get the best results with the alkaline cleaning solutions, the CO2 must be removed or otherwise vented prior to cleaning. This adds additional time and labor to the cleaning process. In addition, these alkaline cleaning solutions generally require the use of hot water for effective performance. The alkaline cleaning solutions also may leave residues and are therefore not free-rinsing.
A number of acidic cleaning solutions have been developed for brewing vats and kegs, including, for example, the Ultra Niter™ cleaning product available from Birko Corp. of Henderson, Colo. as well as those compositions identified in the U.S. Pat. No. 5,645,648 to Laut et al., U.S. Pat. No. 6,168,808 to Hamon Godin et al., U.S. Pat. No. 7,943,565 to Kany et al., U.S. Pat. No. 8,211,239 to Johnson and US Patent Publication Numbers 2003/0064903 to Coughlin et al., 2009/0139546 to Laffitte et al., and 2013/0000681 to Johnson et al., the disclosures of which are all herein incorporated by reference to the extent not inconsistent with the present disclosure. Even with the availability of these acidic cleaning solutions, it would be advantageous to further improve upon the performance of these acidic cleaning solutions and the processes for cleaning hard surfaces, particularly vats and kegs containing CO2.